Conference ssdevo::4wd

    Anybody have info on differential gear oil for limited slip
    differentials ?
    
    Victim: 1975 CJ axle (Dana 44) with factory "Trak-Lok"
    
    The 1975 manuals all state "do not use normal gear oil in a Trak-Lok"
    but it does list 75W/90 through 85W/90 weights for the Trak-Lok.  I
    assume they are referencing additives ?
    
    Here in 1997, I see most "normal" gear oils as being labelled to "also
    protect limited slip differentials".    At my "real" parts store (as
    opposed to volume chain stores) they had a 4 oz. bottle of additive for
    limited slip differentials "to prevent clutch chatter" - store sells a
    lot to the Chevy dealer for Vette's, etc.  They also said that the
    newer gear oils GF-5 and better are OK as-is for the limited slip
    diffs.
    
    I am OK to use a good GF-5 85W/90 and the additive, or does someone
    really sell a different fluid.   I called Jeep dealer - no help there
    in parts or service - "gee, there's nothing new that has that kind of
    differential."
    
    Story: My friend put these 1975 axles under his 1969 CJ5 when we built
    it a few years ago.  Never realized it was a Trak-Lok.  Have been
    running regular gear oil.  Recent noise "ouch" from rear diff and a
    dragging inside wheel when turning indicated definite diff problem. 
    Yup, spider/diff gears are chewed/broken.   Realized when pulling it
    apart anbd ordering up new parts that it had clutches in it.   I don't
    think the fluid contributed to the failure, but since I am putting new
    clutches/springs/gears in it I may as well start out fresh/clean with
    the right fluid to make the limited slip work properly.   (P.S. I think
    the 32" tires, 4" lift, and the way his clutch linkage likes to pop it
    into gear contributed more to the failure .... and a 22-year old axle.
    
    Thanks for any tips on the fluid.

    re: .119 by SOLVIT::TALLO
    
    FWIW, I used GM LSD additive on my '85 Supra.  That was recommended to
    me at the time...
    
    Bill

>    Story: My friend put these 1975 axles under his 1969 CJ5 when we built
>    it a few years ago.  Never realized it was a Trak-Lok.  Have been
>    running regular gear oil.  Recent noise "ouch" from rear diff and a
>    dragging inside wheel when turning indicated definite diff problem. 
>    Yup, spider/diff gears are chewed/broken.   Realized when pulling it
>    apart anbd ordering up new parts that it had clutches in it.   I don't
>    think the fluid contributed to the failure, but since I am putting new
>    clutches/springs/gears in it I may as well start out fresh/clean with
>    the right fluid to make the limited slip work properly.   (P.S. I think
>    the 32" tires, 4" lift, and the way his clutch linkage likes to pop it
>    into gear contributed more to the failure .... and a 22-year old axle.
>


You're right.  It wasn't the gear lube that caused the failure.  the only 
difference between limited slip lube and the standard stuff is the additive 
to keep the clutches working correctly and everything you can buy today has 
the additive in it (when it says "ok for limited slip")

It's getting tough (just like it's getting tough to fine type-F ATF) to 
fine non-posi gear lube in parts stores.  You have to go straight to the 
lubricant suppliers.

    Thanks Skip, I knew that I could depend on one of the "veterans" to
    explain the difference in the fluids.   Differential is all back
    together and running fine (and quiet!)
    By the way SKip, I should thank you for some other assistance on the
    Jeep recently...  I was putting in a relay to power/switch an electric
    heater, and while figuring out how to wire the relay I cracked open
    "How to do Electrical Systems" by Skip Readio !  Right there - how to
    wire a 5-terminal relay.  Thanks.